Status : Verified
| Personal Name | De Vera, Bill John B. |
|---|---|
| Resource Title | Estimation of withdrawal strength of different nail diameters in coconut (Cocos nucifera) lumber subjected to accelerated aging cycles using ultrasonic tests and multiple linear regression analysis |
| Date Issued | 30 June 2025 |
| Abstract | This study aims to investigate the effects of accelerated aging on withdrawal strength of different nail diameters in coconut lumber, assess the sensitivity of ultrasonic test parameters on the damage induced by accelerated aging in wood-nail materials, and develop a regression model for estimating nail withdrawal strength in coconut lumber subjected to accelerated aging. The prepared samples were subjected to different number of accelerated aging cycles. Ultrasonic and withdrawal tests were then implemented. The results show that all nail groups exhibited lower withdrawal strength after one cycle due to high fiber deterioration rate. From two to six cycles, cracking and corrosion influenced withdrawal strength. The smallest nail diameter group demonstrated a continuous increase in withdrawal strength because it developed less cracks but more rust resulting in net increase in withdrawal strength. However, larger nail diameter groups showed a fluctuating trend in withdrawal strength from two to four cycles since they developed more cracks but less rust. After six cycles, these groups showed an increase in withdrawal strength due to continuous corrosion development while fiber deterioration remained roughly the same. Moreover, the results indicate that ultrasonic pulse velocity (UPV) is the most reliable parameter for late damage monitoring while sideband peak count-index (SPC-I) is the most effective parameter for early damage detection in wood-nail materials. Combining SPC-I and UPV will provide a more holistic approach for monitoring damage progression of non-engineered structures in the Philippines. Lastly, based on several performance indicators and adequacy tests, an overall best model was selected. The best model achieved an R2 value of 0.6381. The results also revealed that the lower-prediction bound of the developed model (i.e., best model) in this study may supplement the structural codes and be used to estimate withdrawal strength of coconut lumber in non- |
| Degree Course | MS Civil Engineering |
| Language | English |
| Keyword | Withdrawal strength; Coconut lumber |
| Material Type | Thesis/Dissertation |
Preliminary Pages
8.20 Mb
Category : P - Author wishes to publish the work personally.
Access Permission : Limited Access